FUKUSHIMA – Radiation doses in parts of Fukushima Prefecture now deemed uninhabitable because of contamination will fall by over half by 2021, government estimates released Monday show.
Annual doses per person would fall below 20 millisieverts if decontamination work is done, according to the estimates by the Cabinet Office.
It is the first time that radiation exposure estimates have been compiled for the areas where annual doses stand above 50 millisieverts. An annual reading of 20 millisieverts or less is one of the conditions for the evacuation advisory to be lifted.
The estimates were presented at a meeting Monday in the city of Fukushima of a private panel that advises Kazuyoshi Akaba, the minister of economy, trade and industry, on measures to help reconstruct municipalities around Tokyo Electric Power Co.’s Fukushima No. 1 nuclear plant.
According to the Cabinet Office, atmospheric radiation levels in the most contaminated areas are expected to decrease by half or more within 10 years of the accident, due to the natural decay of the radioactive substances as well as rain and wind sweeping some of the substances away. With decontamination work, the levels would drop further, it said. As of last November, atmospheric radiation levels in the areas stood at 3.8-19 microsieverts per hour.
Annual radiation doses for residents who spend eight hours outdoors a day would reach up to 37 millisieverts if cleanup measures are not taken. Decontamination efforts would see the annual exposure level fall to 3-19 millisieverts, the Cabinet Office said.
Decontamination work was done in parts of the highly polluted areas on a trial basis between last October and January. But no full-fledged decontamination program has been drawn up for the areas.